Daryl

I looking at 6-A-3 diagram and it appears that secondary lever is actually the left hand and clubshaft, the fulcrum at the left wrist joint while primary lever is left arm and clubshaft and fulcrum is the left shoulder joint.
So clubshaft by itself cannot be a lever. The shaft must align in a straight line to the end of the humerus(left arm) or the pisiform (left wrist)

The Golfclub is an extension of your Arms. The Primary Lever moves the Golfclub, the Secondary Lever moves the Clubhead.

6.A.2
Fulcrum: Left Shoulder
Force: Hands/Force is Applied (Source of Force = Left Arm)
Weight: Golfclub

6.A.3
Fulcrum: Left Wrist
Force: Hands/Force is Applied (Source of Force = Right Arm or Left)
Weight: Clubhead

Daryl,
It is my belief that fulcrum is arbitary. As long as I have a clear idea what my levers are, what the load is and what the force is then I can even use the left elbow as a fulcrum